package cn.featherfly.servlet;

import java.io.InputStream;
import java.net.MalformedURLException;
import java.net.URL;
import java.util.Enumeration;
import java.util.EventListener;
import java.util.Set;

/**
 * Defines a set of methods that a servlet uses to communicate with its
 * servlet container, for example, to get the MIME type of a file,
 * dispatch requests, or write to a log file.
 * <p>
 * There is one context per "web application" per Java Virtual Machine. (A
 * "web application" is a collection of servlets and content installed under a
 * specific subset of the server's URL namespace such as <code>/catalog</code>
 * and possibly installed via a <code>.war</code> file.)
 * <p>
 * In the case of a web
 * application marked "distributed" in its deployment descriptor, there will
 * be one context instance for each virtual machine. In this situation, the
 * context cannot be used as a location to share global information (because
 * the information won't be truly global). Use an external resource like
 * a database instead.
 * <p>
 * The <code>ServletContext</code> object is contained within
 * the {@link ServletConfig} object, which the Web server provides the
 * servlet when the servlet is initialized.
 *
 * @author Various
 * @see Servlet#getServletConfig
 * @see ServletConfig#getServletContext
 */
public interface ServletContext {

    /**
     * The name of the <tt>ServletContext</tt> attribute which stores
     * the private temporary directory (of type <tt>java.io.File</tt>)
     * provided by the servlet container for the <tt>ServletContext</tt>
     */
    String TEMPDIR = "javax.servlet.context.tempdir";

    /**
     * The name of the <code>ServletContext</code> attribute whose value
     * (of type <code>java.util.List&lt;java.lang.String&gt;</code>) contains
     * the list of names of JAR files in <code>WEB-INF/lib</code> ordered by
     * their web fragment names (with possible exclusions if
     * <code>&lt;absolute-ordering&gt;</code> without any
     * <code>&lt;others/&gt;</code> is being used), or null if no
     * absolute or relative ordering has been specified
     */
    String ORDERED_LIBS = "javax.servlet.context.orderedLibs";

    /**
     * Returns the context path of the web application.
     * <p>
     * The context path is the portion of the request URI that is used
     * to select the context of the request. The context path always comes
     * first in a request URI. If this context is the "root" context
     * rooted at the base of the Web server's URL name space, this path
     * will be an empty string. Otherwise, if the context is not rooted at
     * the root of the server's name space, the path starts with a /
     * character but does not end with a / character.
     * <p>
     * It is possible that a servlet container may match a context by
     * more than one context path. In such cases the
     * {@link javax.servlet.http.HttpServletRequest#getContextPath()}
     * will return the actual context path used by the request and it may
     * differ from the path returned by this method.
     * The context path returned by this method should be considered as the
     * prime or preferred context path of the application.
     *
     * @return The context path of the web application, or "" for the
     *         root context
     * @see javax.servlet.http.HttpServletRequest#getContextPath()
     * @since Servlet 2.5
     */
    String getContextPath();

    /**
     * Returns a <code>ServletContext</code> object that
     * corresponds to a specified URL on the server.
     * <p>
     * This method allows servlets to gain
     * access to the context for various parts of the server, and as
     * needed obtain {@link RequestDispatcher} objects from the context.
     * The given path must be begin with <tt>/</tt>, is interpreted relative
     * to the server's document root and is matched against the context
     * roots of other web applications hosted on this container.
     * <p>
     * In a security conscious environment, the servlet container may
     * return <code>null</code> for a given URL.
     *
     * @param uripath a <code>String</code> specifying the context path of
     *        another web application in the container.
     * @return the <code>ServletContext</code> object that
     *         corresponds to the named URL, or null if either
     *         none exists or the container wishes to restrict
     *         this access.
     * @see RequestDispatcher
     */
    ServletContext getContext(String uripath);

    /**
     * Returns the major version of the Servlet API that this
     * servlet container supports. All implementations that comply
     * with Version 4.0 must have this method return the integer 4.
     *
     * @return 4
     */
    int getMajorVersion();

    /**
     * Returns the minor version of the Servlet API that this
     * servlet container supports. All implementations that comply
     * with Version 4.0 must have this method return the integer 0.
     *
     * @return 0
     */
    int getMinorVersion();

    /**
     * Gets the major version of the Servlet specification that the
     * application represented by this ServletContext is based on.
     * <p>
     * The value returned may be different from {@link #getMajorVersion},
     * which returns the major version of the Servlet specification
     * supported by the Servlet container.
     *
     * @return the major version of the Servlet specification that the
     *         application represented by this ServletContext is based on
     * @throws UnsupportedOperationException if this ServletContext was
     *         passed to the {@link ServletContextListener#contextInitialized} method
     *         of a {@link ServletContextListener} that was neither declared in
     *         <code>web.xml</code> or <code>web-fragment.xml</code>, nor annotated
     *         with {@link javax.servlet.annotation.WebListener}
     * @since Servlet 3.0
     */
    int getEffectiveMajorVersion();

    /**
     * Gets the minor version of the Servlet specification that the
     * application represented by this ServletContext is based on.
     * <p>
     * The value returned may be different from {@link #getMinorVersion},
     * which returns the minor version of the Servlet specification
     * supported by the Servlet container.
     *
     * @return the minor version of the Servlet specification that the
     *         application represented by this ServletContext is based on
     * @throws UnsupportedOperationException if this ServletContext was
     *         passed to the {@link ServletContextListener#contextInitialized} method
     *         of a {@link ServletContextListener} that was neither declared in
     *         <code>web.xml</code> or <code>web-fragment.xml</code>, nor annotated
     *         with {@link javax.servlet.annotation.WebListener}
     * @since Servlet 3.0
     */
    int getEffectiveMinorVersion();

    /**
     * Returns the MIME type of the specified file, or <code>null</code> if
     * the MIME type is not known. The MIME type is determined
     * by the configuration of the servlet container, and may be specified
     * in a web application deployment descriptor. Common MIME
     * types include <code>text/html</code> and <code>image/gif</code>.
     *
     * @param file a <code>String</code> specifying the name of a file
     * @return a <code>String</code> specifying the file's MIME type
     */
    String getMimeType(String file);

    /**
     * Returns a directory-like listing of all the paths to resources
     * within the web application whose longest sub-path matches the
     * supplied path argument.
     * <p>
     * Paths indicating subdirectory paths end with a <tt>/</tt>.
     * <p>
     * The returned paths are all relative to the root of the web
     * application, or relative to the <tt>/META-INF/resources</tt>
     * directory of a JAR file inside the web application's
     * <tt>/WEB-INF/lib</tt> directory, and have a leading <tt>/</tt>.
     * <p>
     * The returned set is not backed by the {@code ServletContext} object,
     * so changes in the returned set are not reflected in the
     * {@code ServletContext} object, and vice-versa.
     * </p>
     * <p>
     * For example, for a web application containing:
     *
     * <pre>{@code
     *   /welcome.html
     *   /catalog/index.html
     *   /catalog/products.html
     *   /catalog/offers/books.html
     *   /catalog/offers/music.html
     *   /customer/login.jsp
     *   /WEB-INF/web.xml
     *   /WEB-INF/classes/com.acme.OrderServlet.class
     *   /WEB-INF/lib/catalog.jar!/META-INF/resources/catalog/moreOffers/books.html
     * }</pre>
     *
     * <tt>getResourcePaths("/")</tt> would return
     * <tt>{"/welcome.html", "/catalog/", "/customer/", "/WEB-INF/"}</tt>,
     * and <tt>getResourcePaths("/catalog/")</tt> would return
     * <tt>{"/catalog/index.html", "/catalog/products.html",
     * "/catalog/offers/", "/catalog/moreOffers/"}</tt>.
     *
     * @param path the partial path used to match the resources,
     *        which must start with a <tt>/</tt>
     * @return a Set containing the directory listing, or null if there
     *         are no resources in the web application whose path
     *         begins with the supplied path.
     * @since Servlet 2.3
     */
    Set<String> getResourcePaths(String path);

    /**
     * Returns a URL to the resource that is mapped to the given path.
     * <p>
     * The path must begin with a <tt>/</tt> and is interpreted
     * as relative to the current context root,
     * or relative to the <tt>/META-INF/resources</tt> directory
     * of a JAR file inside the web application's <tt>/WEB-INF/lib</tt>
     * directory.
     * This method will first search the document root of the
     * web application for the requested resource, before searching
     * any of the JAR files inside <tt>/WEB-INF/lib</tt>.
     * The order in which the JAR files inside <tt>/WEB-INF/lib</tt>
     * are searched is undefined.
     * <p>
     * This method allows the servlet container to make a resource
     * available to servlets from any source. Resources
     * can be located on a local or remote
     * file system, in a database, or in a <code>.war</code> file.
     * <p>
     * The servlet container must implement the URL handlers
     * and <code>URLConnection</code> objects that are necessary
     * to access the resource.
     * <p>
     * This method returns <code>null</code>
     * if no resource is mapped to the pathname.
     * <p>
     * Some containers may allow writing to the URL returned by
     * this method using the methods of the URL class.
     * <p>
     * The resource content is returned directly, so be aware that
     * requesting a <code>.jsp</code> page returns the JSP source code.
     * Use a <code>RequestDispatcher</code> instead to include results of
     * an execution.
     * <p>
     * This method has a different purpose than
     * <code>java.lang.Class.getResource</code>,
     * which looks up resources based on a class loader. This
     * method does not use class loaders.
     *
     * @param path a <code>String</code> specifying
     *        the path to the resource
     * @return the resource located at the named path,
     *         or <code>null</code> if there is no resource at that path
     * @exception MalformedURLException if the pathname is not given in
     *            the correct form
     */
    URL getResource(String path) throws MalformedURLException;

    /**
     * Returns the resource located at the named path as
     * an <code>InputStream</code> object.
     * <p>
     * The data in the <code>InputStream</code> can be
     * of any type or length. The path must be specified according
     * to the rules given in <code>getResource</code>.
     * This method returns <code>null</code> if no resource exists at
     * the specified path.
     * <p>
     * Meta-information such as content length and content type
     * that is available via <code>getResource</code>
     * method is lost when using this method.
     * <p>
     * The servlet container must implement the URL handlers
     * and <code>URLConnection</code> objects necessary to access
     * the resource.
     * <p>
     * This method is different from
     * <code>java.lang.Class.getResourceAsStream</code>,
     * which uses a class loader. This method allows servlet containers
     * to make a resource available
     * to a servlet from any location, without using a class loader.
     *
     * @param path a <code>String</code> specifying the path
     *        to the resource
     * @return the <code>InputStream</code> returned to the
     *         servlet, or <code>null</code> if no resource
     *         exists at the specified path
     */
    InputStream getResourceAsStream(String path);

    //    /**
    //     * Returns a {@link RequestDispatcher} object that acts
    //     * as a wrapper for the resource located at the given path.
    //     * A <code>RequestDispatcher</code> object can be used to forward
    //     * a request to the resource or to include the resource in a response.
    //     * The resource can be dynamic or static.
    //     * <p>
    //     * The pathname must begin with a <tt>/</tt> and is interpreted as
    //     * relative to the current context root. Use <code>getContext</code>
    //     * to obtain a <code>RequestDispatcher</code> for resources in foreign
    //     * contexts.
    //     * <p>
    //     * This method returns <code>null</code> if the
    //     * <code>ServletContext</code> cannot return a
    //     * <code>RequestDispatcher</code>.
    //     *
    //     * @param path a <code>String</code> specifying the pathname
    //     *        to the resource
    //     * @return a <code>RequestDispatcher</code> object
    //     *         that acts as a wrapper for the resource
    //     *         at the specified path, or <code>null</code> if
    //     *         the <code>ServletContext</code> cannot return
    //     *         a <code>RequestDispatcher</code>
    //     * @see RequestDispatcher
    //     * @see ServletContext#getContext
    //     */
    //    RequestDispatcher getRequestDispatcher(String path);

    //    /**
    //     * Returns a {@link RequestDispatcher} object that acts
    //     * as a wrapper for the named servlet.
    //     * <p>
    //     * Servlets (and JSP pages also) may be given names via server
    //     * administration or via a web application deployment descriptor.
    //     * A servlet instance can determine its name using
    //     * {@link ServletConfig#getServletName}.
    //     * <p>
    //     * This method returns <code>null</code> if the
    //     * <code>ServletContext</code>
    //     * cannot return a <code>RequestDispatcher</code> for any reason.
    //     *
    //     * @param name a <code>String</code> specifying the name
    //     *        of a servlet to wrap
    //     * @return a <code>RequestDispatcher</code> object
    //     *         that acts as a wrapper for the named servlet,
    //     *         or <code>null</code> if the <code>ServletContext</code>
    //     *         cannot return a <code>RequestDispatcher</code>
    //     * @see RequestDispatcher
    //     * @see ServletContext#getContext
    //     * @see ServletConfig#getServletName
    //     */
    //    RequestDispatcher getNamedDispatcher(String name);

    /**
     * Writes the specified message to a servlet log file, usually
     * an event log. The name and type of the servlet log file is
     * specific to the servlet container.
     *
     * @param msg a <code>String</code> specifying the
     *        message to be written to the log file
     */
    void log(String msg);

    /**
     * Writes an explanatory message and a stack trace
     * for a given <code>Throwable</code> exception
     * to the servlet log file. The name and type of the servlet log
     * file is specific to the servlet container, usually an event log.
     *
     * @param message a <code>String</code> that
     *        describes the error or exception
     * @param throwable the <code>Throwable</code> error
     *        or exception
     */
    void log(String message, Throwable throwable);

    /**
     * Gets the <i>real</i> path corresponding to the given
     * <i>virtual</i> path.
     * <p>
     * For example, if <tt>path</tt> is equal to <tt>/index.html</tt>,
     * this method will return the absolute file path on the server's
     * filesystem to which a request of the form
     * <tt>http://&lt;host&gt;:&lt;port&gt;/&lt;contextPath&gt;/index.html</tt>
     * would be mapped, where <tt>&lt;contextPath&gt;</tt> corresponds to the
     * context path of this ServletContext.
     * <p>
     * The real path returned will be in a form
     * appropriate to the computer and operating system on
     * which the servlet container is running, including the
     * proper path separators.
     * <p>
     * Resources inside the <tt>/META-INF/resources</tt>
     * directories of JAR files bundled in the application's
     * <tt>/WEB-INF/lib</tt> directory must be considered only if the
     * container has unpacked them from their containing JAR file, in
     * which case the path to the unpacked location must be returned.
     * <p>
     * This method returns <code>null</code> if the servlet container
     * is unable to translate the given <i>virtual</i> path to a
     * <i>real</i> path.
     *
     * @param path the <i>virtual</i> path to be translated to a
     *        <i>real</i> path
     * @return the <i>real</i> path, or <tt>null</tt> if the
     *         translation cannot be performed
     */
    String getRealPath(String path);

    /**
     * Returns the name and version of the servlet container on which
     * the servlet is running.
     * <p>
     * The form of the returned string is
     * <i>servername</i>/<i>versionnumber</i>.
     * For example, the JavaServer Web Development Kit may return the string
     * <code>JavaServer Web Dev Kit/1.0</code>.
     * <p>
     * The servlet container may return other optional information
     * after the primary string in parentheses, for example,
     * <code>JavaServer Web Dev Kit/1.0 (JDK 1.1.6; Windows NT 4.0 x86)</code>.
     *
     * @return a <code>String</code> containing at least the
     *         servlet container name and version number
     */
    String getServerInfo();

    /**
     * Returns a <code>String</code> containing the value of the named
     * context-wide initialization parameter, or <code>null</code> if
     * the parameter does not exist.
     * <p>
     * This method can make available configuration information useful
     * to an entire web application. For example, it can provide a
     * webmaster's email address or the name of a system that holds
     * critical data.
     *
     * @param name a <code>String</code> containing the name of the
     *        parameter whose value is requested
     * @return a <code>String</code> containing the value of the
     *         context's initialization parameter, or <code>null</code> if the
     *         context's initialization parameter does not exist.
     * @throws NullPointerException if the argument {@code name} is
     *         {@code null}
     * @see ServletConfig#getInitParameter
     */
    String getInitParameter(String name);

    /**
     * Returns the names of the context's initialization parameters as an
     * <code>Enumeration</code> of <code>String</code> objects, or an
     * empty <code>Enumeration</code> if the context has no initialization
     * parameters.
     *
     * @return an <code>Enumeration</code> of <code>String</code>
     *         objects containing the names of the context's
     *         initialization parameters
     * @see ServletConfig#getInitParameter
     */
    Enumeration<String> getInitParameterNames();

    /**
     * Sets the context initialization parameter with the given name and
     * value on this ServletContext.
     *
     * @param name the name of the context initialization parameter to set
     * @param value the value of the context initialization parameter to set
     * @return true if the context initialization parameter with the given
     *         name and value was set successfully on this ServletContext, and false
     *         if it was not set because this ServletContext already contains a
     *         context initialization parameter with a matching name
     * @throws IllegalStateException if this ServletContext has already
     *         been initialized
     * @throws NullPointerException if the name parameter is {@code null}
     * @throws UnsupportedOperationException if this ServletContext was
     *         passed to the {@link ServletContextListener#contextInitialized} method
     *         of a {@link ServletContextListener} that was neither declared in
     *         <code>web.xml</code> or <code>web-fragment.xml</code>, nor annotated
     *         with {@link javax.servlet.annotation.WebListener}
     * @since Servlet 3.0
     */
    boolean setInitParameter(String name, String value);

    /**
     * Returns the servlet container attribute with the given name, or
     * <code>null</code> if there is no attribute by that name.
     * <p>
     * An attribute allows a servlet container to give the
     * servlet additional information not
     * already provided by this interface. See your
     * server documentation for information about its attributes.
     * A list of supported attributes can be retrieved using
     * <code>getAttributeNames</code>.
     * <p>
     * The attribute is returned as a <code>java.lang.Object</code>
     * or some subclass.
     * <p>
     * Attribute names should follow the same convention as package
     * names. The Java Servlet API specification reserves names
     * matching <code>java.*</code>, <code>javax.*</code>,
     * and <code>sun.*</code>.
     *
     * @param name a <code>String</code> specifying the name
     *        of the attribute
     * @return an <code>Object</code> containing the value of the
     *         attribute, or <code>null</code> if no attribute
     *         exists matching the given name.
     * @see ServletContext#getAttributeNames
     * @throws NullPointerException if the argument {@code name} is
     *         {@code null}
     */
    Object getAttribute(String name);

    /**
     * Returns an <code>Enumeration</code> containing the
     * attribute names available within this ServletContext.
     * <p>
     * Use the {@link #getAttribute} method with an attribute name
     * to get the value of an attribute.
     *
     * @return an <code>Enumeration</code> of attribute
     *         names
     * @see #getAttribute
     */
    Enumeration<String> getAttributeNames();

    /**
     * Binds an object to a given attribute name in this ServletContext. If
     * the name specified is already used for an attribute, this
     * method will replace the attribute with the new to the new attribute.
     * <p>
     * If listeners are configured on the <code>ServletContext</code> the
     * container notifies them accordingly.
     * <p>
     * If a null value is passed, the effect is the same as calling
     * <code>removeAttribute()</code>.
     * <p>
     * Attribute names should follow the same convention as package
     * names. The Java Servlet API specification reserves names
     * matching <code>java.*</code>, <code>javax.*</code>, and
     * <code>sun.*</code>.
     *
     * @param name a <code>String</code> specifying the name
     *        of the attribute
     * @param object an <code>Object</code> representing the
     *        attribute to be bound
     * @throws NullPointerException if the name parameter is {@code null}
     */
    void setAttribute(String name, Object object);

    /**
     * Removes the attribute with the given name from
     * this ServletContext. After removal, subsequent calls to
     * {@link #getAttribute} to retrieve the attribute's value
     * will return <code>null</code>.
     * <p>
     * If listeners are configured on the <code>ServletContext</code> the
     * container notifies them accordingly.
     *
     * @param name a <code>String</code> specifying the name
     *        of the attribute to be removed
     */
    void removeAttribute(String name);

    /**
     * Returns the name of this web application corresponding to this
     * ServletContext as specified in the deployment descriptor for this
     * web application by the display-name element.
     *
     * @return The name of the web application or null if no name has been
     *         declared in the deployment descriptor.
     * @since Servlet 2.3
     */
    String getServletContextName();

    //    /**
    //     * Gets the {@link SessionCookieConfig} object through which various
    //     * properties of the session tracking cookies created on behalf of this
    //     * <tt>ServletContext</tt> may be configured.
    //     * <p>
    //     * Repeated invocations of this method will return the same
    //     * <tt>SessionCookieConfig</tt> instance.
    //     *
    //     * @return the <tt>SessionCookieConfig</tt> object through which
    //     *         various properties of the session tracking cookies created on
    //     *         behalf of this <tt>ServletContext</tt> may be configured
    //     * @throws UnsupportedOperationException if this ServletContext was
    //     *         passed to the {@link ServletContextListener#contextInitialized} method
    //     *         of a {@link ServletContextListener} that was neither declared in
    //     *         <code>web.xml</code> or <code>web-fragment.xml</code>, nor annotated
    //     *         with {@link javax.servlet.annotation.WebListener}
    //     * @since Servlet 3.0
    //     */
    //    SessionCookieConfig getSessionCookieConfig();

    //    /**
    //     * Sets the session tracking modes that are to become effective for this
    //     * <tt>ServletContext</tt>.
    //     * <p>
    //     * The given <tt>sessionTrackingModes</tt> replaces any
    //     * session tracking modes set by a previous invocation of this
    //     * method on this <tt>ServletContext</tt>.
    //     *
    //     * @param sessionTrackingModes the set of session tracking modes to
    //     *        become effective for this <tt>ServletContext</tt>
    //     * @throws IllegalStateException if this ServletContext has already
    //     *         been initialized
    //     * @throws UnsupportedOperationException if this ServletContext was
    //     *         passed to the {@link ServletContextListener#contextInitialized} method
    //     *         of a {@link ServletContextListener} that was neither declared in
    //     *         <code>web.xml</code> or <code>web-fragment.xml</code>, nor annotated
    //     *         with {@link javax.servlet.annotation.WebListener}
    //     * @throws IllegalArgumentException if <tt>sessionTrackingModes</tt>
    //     *         specifies a combination of <tt>SessionTrackingMode.SSL</tt> with a
    //     *         session tracking mode other than <tt>SessionTrackingMode.SSL</tt>,
    //     *         or if <tt>sessionTrackingModes</tt> specifies a session tracking mode
    //     *         that is not supported by the servlet container
    //     * @since Servlet 3.0
    //     */
    //    void setSessionTrackingModes(Set<SessionTrackingMode> sessionTrackingModes);

    //    /**
    //     * Gets the session tracking modes that are supported by default for this
    //     * <tt>ServletContext</tt>.
    //     * <p>
    //     * The returned set is not backed by the {@code ServletContext} object,
    //     * so changes in the returned set are not reflected in the
    //     * {@code ServletContext} object, and vice-versa.
    //     * </p>
    //     *
    //     * @return set of the session tracking modes supported by default for
    //     *         this <tt>ServletContext</tt>
    //     * @throws UnsupportedOperationException if this ServletContext was
    //     *         passed to the {@link ServletContextListener#contextInitialized} method
    //     *         of a {@link ServletContextListener} that was neither declared in
    //     *         <code>web.xml</code> or <code>web-fragment.xml</code>, nor annotated
    //     *         with {@link javax.servlet.annotation.WebListener}
    //     * @since Servlet 3.0
    //     */
    //    Set<SessionTrackingMode> getDefaultSessionTrackingModes();

    //    /**
    //     * Gets the session tracking modes that are in effect for this
    //     * <tt>ServletContext</tt>.
    //     * <p>
    //     * The session tracking modes in effect are those provided to
    //     * {@link #setSessionTrackingModes setSessionTrackingModes}.
    //     * <p>
    //     * The returned set is not backed by the {@code ServletContext} object,
    //     * so changes in the returned set are not reflected in the
    //     * {@code ServletContext} object, and vice-versa.
    //     * </p>
    //     *
    //     * @return set of the session tracking modes in effect for this
    //     *         <tt>ServletContext</tt>
    //     * @throws UnsupportedOperationException if this ServletContext was
    //     *         passed to the {@link ServletContextListener#contextInitialized} method
    //     *         of a {@link ServletContextListener} that was neither declared in
    //     *         <code>web.xml</code> or <code>web-fragment.xml</code>, nor annotated
    //     *         with {@link javax.servlet.annotation.WebListener}
    //     * @since Servlet 3.0
    //     */
    //    Set<SessionTrackingMode> getEffectiveSessionTrackingModes();

    /**
     * Adds the listener with the given class name to this ServletContext.
     * <p>
     * The class with the given name will be loaded using the
     * classloader associated with the application represented by this
     * ServletContext, and must implement one or more of the following
     * interfaces:
     * <ul>
     * <li>{@link ServletContextAttributeListener}
     * <li>{@link ServletRequestListener}
     * <li>{@link ServletRequestAttributeListener}
     * <li>{@link javax.servlet.http.HttpSessionAttributeListener}
     * <li>{@link javax.servlet.http.HttpSessionIdListener}
     * <li>{@link javax.servlet.http.HttpSessionListener}
     * </ul>
     * <p>
     * If this ServletContext was passed to
     * {@link ServletContainerInitializer#onStartup}, then the class with
     * the given name may also implement {@link ServletContextListener},
     * in addition to the interfaces listed above.
     * <p>
     * As part of this method call, the container must load the class
     * with the specified class name to ensure that it implements one of
     * the required interfaces.
     * <p>
     * If the class with the given name implements a listener interface
     * whose invocation order corresponds to the declaration order (i.e.,
     * if it implements {@link ServletRequestListener},
     * {@link ServletContextListener}, or
     * {@link javax.servlet.http.HttpSessionListener}),
     * then the new listener will be added to the end of the ordered list of
     * listeners of that interface.
     * <p>
     * This method supports resource injection if the class with the
     * given <tt>className</tt> represents a Managed Bean.
     * See the Java EE platform and JSR 299 specifications for additional
     * details about Managed Beans and resource injection.
     *
     * @param className the fully qualified class name of the listener
     * @throws IllegalArgumentException if the class with the given name
     *         does not implement any of the above interfaces, or if it implements
     *         {@link ServletContextListener} and this ServletContext was not
     *         passed to {@link ServletContainerInitializer#onStartup}
     * @throws IllegalStateException if this ServletContext has already
     *         been initialized
     * @throws UnsupportedOperationException if this ServletContext was
     *         passed to the {@link ServletContextListener#contextInitialized} method
     *         of a {@link ServletContextListener} that was neither declared in
     *         <code>web.xml</code> or <code>web-fragment.xml</code>, nor annotated
     *         with {@link javax.servlet.annotation.WebListener}
     * @since Servlet 3.0
     */
    void addListener(String className);

    /**
     * Adds the given listener to this ServletContext.
     * <p>
     * The given listener must be an instance of one or more of the
     * following interfaces:
     * <ul>
     * <li>{@link ServletContextAttributeListener}
     * <li>{@link ServletRequestListener}
     * <li>{@link ServletRequestAttributeListener}
     * <li>{@link javax.servlet.http.HttpSessionAttributeListener}
     * <li>{@link javax.servlet.http.HttpSessionIdListener}
     * <li>{@link javax.servlet.http.HttpSessionListener}
     * </ul>
     * <p>
     * If this ServletContext was passed to
     * {@link ServletContainerInitializer#onStartup}, then the given
     * listener may also be an instance of {@link ServletContextListener},
     * in addition to the interfaces listed above.
     * <p>
     * If the given listener is an instance of a listener interface whose
     * invocation order corresponds to the declaration order (i.e., if it
     * is an instance of {@link ServletRequestListener},
     * {@link ServletContextListener}, or
     * {@link javax.servlet.http.HttpSessionListener}),
     * then the listener will be added to the end of the ordered list of
     * listeners of that interface.
     *
     * @param <T> the class of the EventListener to add
     * @param t the listener to be added
     * @throws IllegalArgumentException if the given listener is not
     *         an instance of any of the above interfaces, or if it is an instance
     *         of {@link ServletContextListener} and this ServletContext was not
     *         passed to {@link ServletContainerInitializer#onStartup}
     * @throws IllegalStateException if this ServletContext has already
     *         been initialized
     * @throws UnsupportedOperationException if this ServletContext was
     *         passed to the {@link ServletContextListener#contextInitialized} method
     *         of a {@link ServletContextListener} that was neither declared in
     *         <code>web.xml</code> or <code>web-fragment.xml</code>, nor annotated
     *         with {@link javax.servlet.annotation.WebListener}
     * @since Servlet 3.0
     */
    <T extends EventListener> void addListener(T t);

    /**
     * Adds a listener of the given class type to this ServletContext.
     * <p>
     * The given <tt>listenerClass</tt> must implement one or more of the
     * following interfaces:
     * <ul>
     * <li>{@link ServletContextAttributeListener}
     * <li>{@link ServletRequestListener}
     * <li>{@link ServletRequestAttributeListener}
     * <li>{@link javax.servlet.http.HttpSessionAttributeListener}
     * <li>{@link javax.servlet.http.HttpSessionIdListener}
     * <li>{@link javax.servlet.http.HttpSessionListener}
     * </ul>
     * <p>
     * If this ServletContext was passed to
     * {@link ServletContainerInitializer#onStartup}, then the given
     * <tt>listenerClass</tt> may also implement
     * {@link ServletContextListener}, in addition to the interfaces listed
     * above.
     * <p>
     * If the given <tt>listenerClass</tt> implements a listener
     * interface whose invocation order corresponds to the declaration order
     * (i.e., if it implements {@link ServletRequestListener},
     * {@link ServletContextListener}, or
     * {@link javax.servlet.http.HttpSessionListener}),
     * then the new listener will be added to the end of the ordered list
     * of listeners of that interface.
     * <p>
     * This method supports resource injection if the given
     * <tt>listenerClass</tt> represents a Managed Bean.
     * See the Java EE platform and JSR 299 specifications for additional
     * details about Managed Beans and resource injection.
     *
     * @param listenerClass the listener class to be instantiated
     * @throws IllegalArgumentException if the given <tt>listenerClass</tt>
     *         does not implement any of the above interfaces, or if it implements
     *         {@link ServletContextListener} and this ServletContext was not passed
     *         to {@link ServletContainerInitializer#onStartup}
     * @throws IllegalStateException if this ServletContext has already
     *         been initialized
     * @throws UnsupportedOperationException if this ServletContext was
     *         passed to the {@link ServletContextListener#contextInitialized} method
     *         of a {@link ServletContextListener} that was neither declared in
     *         <code>web.xml</code> or <code>web-fragment.xml</code>, nor annotated
     *         with {@link javax.servlet.annotation.WebListener}
     * @since Servlet 3.0
     */
    void addListener(Class<? extends EventListener> listenerClass);

    //    /**
    //     * Instantiates the given EventListener class.
    //     * <p>
    //     * The specified EventListener class must implement at least one of
    //     * the {@link ServletContextListener},
    //     * {@link ServletContextAttributeListener},
    //     * {@link ServletRequestListener},
    //     * {@link ServletRequestAttributeListener},
    //     * {@link javax.servlet.http.HttpSessionAttributeListener},
    //     * {@link javax.servlet.http.HttpSessionIdListener}, or
    //     * {@link javax.servlet.http.HttpSessionListener}
    //     * interfaces.
    //     * <p>
    //     * The returned EventListener instance may be further customized
    //     * before it is registered with this ServletContext via a call to
    //     * {@link #addListener(EventListener)}.
    //     * <p>
    //     * The given EventListener class must define a zero argument
    //     * constructor, which is used to instantiate it.
    //     * <p>
    //     * This method supports resource injection if the given
    //     * <tt>clazz</tt> represents a Managed Bean.
    //     * See the Java EE platform and JSR 299 specifications for additional
    //     * details about Managed Beans and resource injection.
    //     *
    //     * @param <T> the class of the EventListener to create
    //     * @param clazz the EventListener class to instantiate
    //     * @return the new EventListener instance
    //     * @throws ServletException if the given <tt>clazz</tt> fails to be
    //     *         instantiated
    //     * @throws UnsupportedOperationException if this ServletContext was
    //     *         passed to the {@link ServletContextListener#contextInitialized} method
    //     *         of a {@link ServletContextListener} that was neither declared in
    //     *         <code>web.xml</code> or <code>web-fragment.xml</code>, nor annotated
    //     *         with {@link javax.servlet.annotation.WebListener}
    //     * @throws IllegalArgumentException if the specified EventListener class
    //     *         does not implement any of the
    //     *         {@link ServletContextListener},
    //     *         {@link ServletContextAttributeListener},
    //     *         {@link ServletRequestListener},
    //     *         {@link ServletRequestAttributeListener},
    //     *         {@link javax.servlet.http.HttpSessionAttributeListener},
    //     *         {@link javax.servlet.http.HttpSessionIdListener}, or
    //     *         {@link javax.servlet.http.HttpSessionListener}
    //     *         interfaces.
    //     * @since Servlet 3.0
    //     */
    //    <T extends EventListener> T createListener(Class<T> clazz) throws ServletException;

    //    /**
    //     * Gets the <code>&lt;jsp-config&gt;</code> related configuration
    //     * that was aggregated from the <code>web.xml</code> and
    //     * <code>web-fragment.xml</code> descriptor files of the web application
    //     * represented by this ServletContext.
    //     *
    //     * @return the <code>&lt;jsp-config&gt;</code> related configuration
    //     *         that was aggregated from the <code>web.xml</code> and
    //     *         <code>web-fragment.xml</code> descriptor files of the web application
    //     *         represented by this ServletContext, or null if no such configuration
    //     *         exists
    //     * @throws UnsupportedOperationException if this ServletContext was
    //     *         passed to the {@link ServletContextListener#contextInitialized} method
    //     *         of a {@link ServletContextListener} that was neither declared in
    //     *         <code>web.xml</code> or <code>web-fragment.xml</code>, nor annotated
    //     *         with {@link javax.servlet.annotation.WebListener}
    //     * @see javax.servlet.descriptor.JspConfigDescriptor
    //     * @since Servlet 3.0
    //     */
    //    JspConfigDescriptor getJspConfigDescriptor();

    /**
     * Gets the class loader of the web application represented by this
     * ServletContext.
     * <p>
     * If a security manager exists, and the caller's class loader
     * is not the same as, or an ancestor of the requested class loader,
     * then the security manager's <code>checkPermission</code> method is
     * called with a <code>RuntimePermission("getClassLoader")</code>
     * permission to check whether access to the requested class loader
     * should be granted.
     *
     * @return the class loader of the web application represented by this
     *         ServletContext
     * @throws UnsupportedOperationException if this ServletContext was
     *         passed to the {@link ServletContextListener#contextInitialized} method
     *         of a {@link ServletContextListener} that was neither declared in
     *         <code>web.xml</code> or <code>web-fragment.xml</code>, nor annotated
     *         with {@link javax.servlet.annotation.WebListener}
     * @throws SecurityException if a security manager denies access to
     *         the requested class loader
     * @since Servlet 3.0
     */
    ClassLoader getClassLoader();

    /**
     * Declares role names that are tested using <code>isUserInRole</code>.
     * <p>
     * Roles that are implicitly declared as a result of their use within
     * the {@link ServletRegistration.Dynamic#setServletSecurity
     * setServletSecurity} or {@link ServletRegistration.Dynamic#setRunAsRole
     * setRunAsRole} methods of the {@link ServletRegistration} interface need
     * not be declared.
     *
     * @param roleNames the role names being declared
     * @throws UnsupportedOperationException if this ServletContext was
     *         passed to the {@link ServletContextListener#contextInitialized} method
     *         of a {@link ServletContextListener} that was neither declared in
     *         <code>web.xml</code> or <code>web-fragment.xml</code>, nor annotated
     *         with {@link javax.servlet.annotation.WebListener}
     * @throws IllegalArgumentException if any of the argument roleNames is
     *         null or the empty string
     * @throws IllegalStateException if the ServletContext has already
     *         been initialized
     * @since Servlet 3.0
     */
    void declareRoles(String... roleNames);

    /**
     * Returns the configuration name of the logical host on which the
     * ServletContext is deployed.
     * Servlet containers may support multiple logical hosts. This method must
     * return the same name for all the servlet contexts deployed on a logical
     * host, and the name returned by this method must be distinct, stable per
     * logical host, and suitable for use in associating server configuration
     * information with the logical host. The returned value is NOT expected
     * or required to be equivalent to a network address or hostname of the
     * logical host.
     *
     * @return a <code>String</code> containing the configuration name of the
     *         logical host on which the servlet context is deployed.
     * @throws UnsupportedOperationException if this ServletContext was
     *         passed to the {@link ServletContextListener#contextInitialized} method
     *         of a {@link ServletContextListener} that was neither declared in
     *         <code>web.xml</code> or <code>web-fragment.xml</code>, nor annotated
     *         with {@link javax.servlet.annotation.WebListener}
     * @since Servlet 3.1
     */
    String getVirtualServerName();

    /**
     * Gets the session timeout in minutes that are supported by default for
     * this <tt>ServletContext</tt>.
     *
     * @return the session timeout in minutes that are supported by default for
     *         this <tt>ServletContext</tt>
     * @throws UnsupportedOperationException if this ServletContext was
     *         passed to the {@link ServletContextListener#contextInitialized} method
     *         of a {@link ServletContextListener} that was neither declared in
     *         <code>web.xml</code> or <code>web-fragment.xml</code>, nor annotated
     *         with {@link javax.servlet.annotation.WebListener}
     * @since Servlet 4.0
     */
    int getSessionTimeout();

    /**
     * Sets the session timeout in minutes for this ServletContext.
     *
     * @param sessionTimeout session timeout in minutes
     * @throws IllegalStateException if this ServletContext has already
     *         been initialized
     * @throws UnsupportedOperationException if this ServletContext was
     *         passed to the {@link ServletContextListener#contextInitialized} method
     *         of a {@link ServletContextListener} that was neither declared in
     *         <code>web.xml</code> or <code>web-fragment.xml</code>, nor annotated
     *         with {@link javax.servlet.annotation.WebListener}
     * @since Servlet 4.0
     */
    void setSessionTimeout(int sessionTimeout);

    /**
     * Gets the request character encoding that are supported by default for
     * this <tt>ServletContext</tt>. This method returns null if no request
     * encoding character encoding has been specified in deployment descriptor
     * or container specific configuration (for all web applications in the
     * container).
     *
     * @return the request character encoding that are supported by default for
     *         this <tt>ServletContext</tt>
     * @throws UnsupportedOperationException if this ServletContext was
     *         passed to the {@link ServletContextListener#contextInitialized} method
     *         of a {@link ServletContextListener} that was neither declared in
     *         <code>web.xml</code> or <code>web-fragment.xml</code>, nor annotated
     *         with {@link javax.servlet.annotation.WebListener}
     * @since Servlet 4.0
     */
    String getRequestCharacterEncoding();

    /**
     * Sets the request character encoding for this ServletContext.
     *
     * @param encoding request character encoding
     * @throws IllegalStateException if this ServletContext has already
     *         been initialized
     * @throws UnsupportedOperationException if this ServletContext was
     *         passed to the {@link ServletContextListener#contextInitialized} method
     *         of a {@link ServletContextListener} that was neither declared in
     *         <code>web.xml</code> or <code>web-fragment.xml</code>, nor annotated
     *         with {@link javax.servlet.annotation.WebListener}
     * @since Servlet 4.0
     */
    void setRequestCharacterEncoding(String encoding);

    /**
     * Gets the response character encoding that are supported by default for
     * this <tt>ServletContext</tt>. This method returns null if no response
     * encoding character encoding has been specified in deployment descriptor
     * or container specific configuration (for all web applications in the
     * container).
     *
     * @return the request character encoding that are supported by default for
     *         this <tt>ServletContext</tt>
     * @throws UnsupportedOperationException if this ServletContext was
     *         passed to the {@link ServletContextListener#contextInitialized} method
     *         of a {@link ServletContextListener} that was neither declared in
     *         <code>web.xml</code> or <code>web-fragment.xml</code>, nor annotated
     *         with {@link javax.servlet.annotation.WebListener}
     * @since Servlet 4.0
     */
    String getResponseCharacterEncoding();

    /**
     * Sets the response character encoding for this ServletContext.
     *
     * @param encoding response character encoding
     * @throws IllegalStateException if this ServletContext has already
     *         been initialized
     * @throws UnsupportedOperationException if this ServletContext was
     *         passed to the {@link ServletContextListener#contextInitialized} method
     *         of a {@link ServletContextListener} that was neither declared in
     *         <code>web.xml</code> or <code>web-fragment.xml</code>, nor annotated
     *         with {@link javax.servlet.annotation.WebListener}
     * @since Servlet 4.0
     */
    void setResponseCharacterEncoding(String encoding);
}
